.container {
  max-width: 840px;
}

.header {
  background-color: #2b2b2b;
  background-image: -webkit-linear-gradient(bottom left, hsla(0, 0%, 0%, .25) 25%, transparent 25%, transparent 75%, hsla(0, 0%, 0%, .25) 75%, hsla(0, 0%, 0%, .25)),
  -webkit-linear-gradient(bottom left, hsla(0, 0%, 0%, .25) 25%, transparent 25%, transparent 75%, hsla(0, 0%, 0%, .25) 75%, hsla(0, 0%, 0%, .25));
  background-image: -o-linear-gradient(bottom left, hsla(0, 0%, 0%, .25) 25%, transparent 25%, transparent 75%, hsla(0, 0%, 0%, .25) 75%, hsla(0, 0%, 0%, .25)),
  -o-linear-gradient(bottom left, hsla(0, 0%, 0%, .25) 25%, transparent 25%, transparent 75%, hsla(0, 0%, 0%, .25) 75%, hsla(0, 0%, 0%, .25));
  background-image: linear-gradient(to top right, hsla(0, 0%, 0%, .25) 25%, transparent 25%, transparent 75%, hsla(0, 0%, 0%, .25) 75%, hsla(0, 0%, 0%, .25)),
  linear-gradient(to top right, hsla(0, 0%, 0%, .25) 25%, transparent 25%, transparent 75%, hsla(0, 0%, 0%, .25) 75%, hsla(0, 0%, 0%, .25));;
  background-position: 0 0, 2px 2px;
  background-size: 4px 4px;
}

.footer {
  padding: 30px 0;
}

.image-set {
  font-size: 0px;
  margin-left: -5px;
  margin-right: -5px;
}

.image-set img {
  display: block;
}

.image-set a {
  display: inline-block;
  margin-left: 5px;
  margin-right: 5px;
  padding: 2px;
  border: 1px solid #ddd;
  transition: border-color .3s ease;
}

.image-set a:hover {
  border-color: #aaa;
}

/* prettify style */

pre ul,
pre ol {
  padding: 0;
}

.com {
  color: #93a1a1;
}

.lit {
  color: #195f91;
}

.pun,
.opn,
.clo {
  color: #93a1a1;
}

.fun {
  color: #dc322f;
}

.str,
.atv {
  color: #D14;
}

.kwd,
.tag {
  color: #1e347b;
}

.typ,
.atn,
.dec,
.var {
  color: teal;
}

.pln {
  color: #48484c;
}

.prettyprint {
  padding: 10px;
  background-color: #f7f7f9;
  border: 1px solid #e1e1e8;
}
